Tuning the electron band structure of graphene for optoelectronics

Graphene, a conjugated sp2 carbon sheet arranged in a two-dimensional honeycomb-like lattice, shows the unique electronic structure in which conical shaped π-electron conduction and valence bands meet at the Dirac point. The properties of graphene are largely controlled by the Fermi level and the density of π-electron states, which can be used for tuning graphene to specific optoelectronic and electrochemical applications. We report a computational study of the electron states and electrochemical response towards ${{\text{I}}^ - }{\text{/I}}_3^ - $ redox mediator used in dye sensitized solar cells. We consider the influence of lattice deformations and magnetic field combined with covalently bonded moieties and charged ions on the heterogeneous electron transfer kinetics.